Electrical trolley equipment



April 12, 1949. B. w. BENBow 2,457,183

ELECTRICAL TROLLEY EQUIPMENT Filed May l, 1945 2 Sheets-Sheet 1 April l2, 1949. B. w. BENBow ELECTRICAL TROLLEY EQUIPMENT E 2 Sheets-Sheet 2 Filed May l, 1945 INVENTOR. ur/s l/l/ enbow www Imi M -H.HH

Patented Apr. 12, 1949 UNITED STATES PATENT OFFICE ELECTRICAL TROLLEY EQUIPMENT Burtis W. Benbow, Benbow, Calif. Application May 1, 1945, Serial No. 591,303

4 Claims. 1

This invention relates generally to electrical trolley assemblies or apparatus such as are used with movable electrical contacting devices for supplying electrical current to electrical equipment such as cranes, hoists, light electric locomotives and the like.

In apparatus of the above type it is common practice to utilize extended trolley conductors of suitable size and supported at intervals by suitable insulators. In the majority of installations the cables are bare and workmen are exposed to the hazards oi accidental contact. It has been proposed to protect the conductors against accidental contact by the use of insulating shrouding, with the shrouding formed in such a manner as to permit continuous electrical contact. A novel shrouded conductor of this type is disclosed for example in my Patent No. 2,255,874. Certain problems are encountered in the installation of such equipment, particularly with respect to feeding current to the conductor at one or more points in order to insure current to the motors of the hoist, crane or other appliances without excessive voltage drop.

It is an object of the invention to provide apparatus of the above type incorporating novel means for feeding current to the insulated trolley conductor at one or more points.

A further object of the invention is to provide an assembly of the above character particularly adapted for use in conjunction with a conductor of the type disclosed in my Patent 2,255,874, where the insulating sheath for the conductor is interrupted on one side by a series of spaced recesses.

Additional objects and features of the invention will appear from the following description in which the preferred embodiment has been set forth in detail in conjunction with the accompanying drawing.

Referring to the drawing:

Fig. 1 is a plan view of equipment incorporating the invention and particularly a plan view of the equipment as shown in Fig. 2.

Fig. 2 is a side elevational view of the equipment as shown in Fig. 1.

Fig. 3 is an end view of the equipment shown in Fig. 1 with the trolley assembly shown in cross section.

Fig. 4 is a cross-sectional View taken on the line 4 4 of Fig. 2.

Fig. 5 is a cross-sectional view on an enlarged scale taken on the line 5-5 of Fig. 2.

Fig. 6 is a side elevational view of the equipment as shown in Fig. 5 with the forward half of the housing removed and with certain parts in section.

Fig. 7 is a cross-sectional View taken on the line 1-1 of Fig. 6.

The apparatus illustrated in the drawing consists generally of a pair of aligned assemblies Ita and iilb, between which is interposed the assembly II. A common trolley cable or conductor i2 extends through the aligned assemblies.

Each of the assemblies Illa, Iilb consists in this instance of an insulating sheath I3 disposed about the conductor i2, and formed of suitable insulating material such as vulcanized natural or synthetic rubber having a fair degree of resiliency. One side (the upper side in this instance) of sheath Eil i's attached to a mounting or backing strip lf3, which can be formed in the manner disclosed in my copending application Serial No. 569,784, led December 26, 1944. Briey, the backing strip is made of sheet metal bent to a generally T-shaped cross section as shown in Figure 4, and with edges I6 crimped upon ribs il formed on the rubber sheath I3. The central rib I3 of the backing strip is formed of metal doubledupon itself as illustrated, and the substantially flat parallel surfaces or shoulders E9 formed on opposite sides of the rib I8, provide trackways to be engaged by guide rollers or wheels of a traveling contacting device, as disclosed in the aforesaid application Serial No. 569,784.

That side of the rubber sheath I3 opposite from the side attached to the backing strip I4 (the lower side of Figure 3), is interrupted bly a series of regularly spaced recesses 2 IA in the manner disclosed in said application Serial No. 569,784, to permit access for making electrical Contact with the lower side of the conductor I2. These recesses are separated by bar-like teeth 22 of insulating material, formed like the teeth of a gear rack and integral with the main body of the sheath I3. A sheath formed in this manner is adapted to cooperate with a type of traveling contacting device such as shown in my Patent 2,255,874, namely one employing an endless chain made up of conducting links provided with teeth adapted to enter the recesses for making electrical engagement with the trolley wire.

The assembly II, interposed between assemblies Illa and IIJb, can consist of a conducting strip 26 made of suitable material such as copper or bronze, normally disposed in a plane coincident with the axis of conductor I2. Assuming that the apparatus is installed with the recesses 2I faced downwardly, the strip is in a vertical plane. The lower end of strip 25 is suitably electrically connected to the conductor I2, preferably by means permitting quick application without soldering. For this purpose the lower end of the strip is provided with a spring clip consisting of a pair of spring jaws 2'! secured as .by means of rivets 28 and solder to the strip 26. The jaws 21 are dimensioned and proportioned so that they must be sprung outwardly to cause the same to be positioned on opposite sides of the conductor I2, as shown in Figure 5. In making an installation attachment of the strip can be accomplished simply by forcing the strip 26 downwardly upon the conductor I2. A terminal block 29 is attached to the upper end of strip 26 and this block has an opening 3| to receive the current feed cable 32. Suitable means such as clamping-fscievfs v33 insures a good grip and good current contactbetween the cable and terminal box 29.

That part of the conductorv extending between assemblies Illa and IIlb, and also the strip 2t, are

enclosed within a housing 3d of insulating material, such as a molded plastic like phenolic coni densation material known as Bakelite Preferably this housing is made in two halves 34a, 34h, which are normally held together by screws '36. The lower portion 3l of thehousing is formed to such width as to continue the side contour of the insulating sheath I3 of the assemblies lila `andflb` yShoulders 38 are provided by portion 31 to provide a continuation of the tracliways I9.

Each-housing part is also provided with lower studs 39 whereby when the two parts are assembledfthese studs underlie the conductor i2, and ineiect form teeth corresponding to and having substantially the same spacing as the teeth Z2 forutherubloer sheath I3.

To provide a simple and effective means for making mechanical attachment between assemblyr I'I andthe assemblies lila, mi), each housing part is provided with a projecting metal tab di dimensioned to fit within the adjacent end oi' the backing'strip rib I8. In addition I provide a pair of locking keys i152, which are held in place by the spring retaining clipsliS. Each or" the keys i2 is provided with a lug or tab dei, engaging within a recess 119 formed in thehousing 3d, and also with a. lug or tab Il extending into the rib of the adjacent backing strip through a slot d8. The retain-- ing clip i3 is made of spring sheet metal bent substantially U-shaped, with inturned lower edges 49.whereby when it is forced over the locking key 42? and the adjacent rib I8,`its lower edges are accommodated and retained within the grooves I, which are formed along the base of the rib i3. "i Useof the invention can be described as follows:

The` assemblies iid, Itib are attached by suitable ,the trackways or shoulders 380i the interposed 4 assembly II. Current is fed tothe trolley conductor from theexterior conductor 32 with a negligible voltage drop because 'of the relatively low. resistance aiorded. My. invention greatly .facilitates making Vinstallations because it is a relatively simplematter to install the assembly II ,between two adjacent alignedassemblies Ita, lIIIIb. In making such an installation it is only necessary to`rst apply the conducting strip 26 in,.the manner previously described, with the spring jaws 2l gripping the conductor i2, after which the -two parts oi the insulating housing 3d are applied one after the other, with the tabs lli sing inserted into the ribs I8. Thereafter the locking keysgdZ are applied and retained in place `by.,pplication of the spring clips43. The rexterior 4 current cable/32 can now be attached to the ter'- minal block 29.

I claim:

1. In electrical trolley apparatus, an extended trolley conductor, an insulating sheath serving to protect the conductor against accidental contact, a backing strip attached to the upper side of the sheath and serving as a mounting for the same, said strip forming a pair of parallel trackways Aadapted to be engaged by guide wheels of a traveling contacting device, said strip and said sheath being interrupted by a gap, a vertical conductor strip located within the gap, the lower end edge oi the strip being electrically connected to the conductor in such a manner as to leave the lower sideof the conductor unobstructed for contact with a movable electrical-contacting device, an insulating housing for the strip and for that portion of the conductor extending across said gap, said housingl providing trackways in alignment with the aforesaid trackways of said backing strip, said last named trackways being disposed on opposite sides of said strip.

2. Apparatus as in claim 1 in which both said insulating sheath and said insulating housing are provided with spaced recesses extending through the lower side oi the same for access to the trolley conductor, said recesses being spaced apart by teeth or bars of insulating material.

3. Apparatus as in claim 1 in which means is provided for releasably locking the end portions of the insulating housing to the adjacent baclnng strips. f

4. In electrical trolley apparatus, an extended trolley conductor, an insulating sheath serving to protect the conductor against accidental contact, a bacl'zing strip attached to the upper side of the sheath and serving as a mounting for the same, said strip being formed to provide a rib and a ypair of parallel trackways on opposite sides trical contacting device, an insulating housing for the strip and for that portion of the conductor extending across the gap, said housing providing trackways in alignment with the aforesaid trackways of said backing strip, theportion of the housing on opposite sides of the strip forming a continuation of and being in alignment with said rib.

' rBUR/FIS W. BENBOW.

REFERENCES CITED The following references are of record in the `ileoi this patent:

UNITED STATES PATENTS 2,364,720 Wehr Dec; 8, 1942 

